From: Goffredo Baroncelli <kreijack@inwind.it>
To: Marat Khalili <mkh@rqc.ru>, Hugo Mills <hugo@carfax.org.uk>,
linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: BUG: BTRFS and O_DIRECT could lead to wrong checksum and wrong data
Date: Fri, 15 Sep 2017 19:37:04 +0200 [thread overview]
Message-ID: <dae5a361-6ff4-c64c-81fa-ed58b1d54dff@inwind.it> (raw)
In-Reply-To: <7aa8063a-2f1f-c611-d24a-d5e6a9ceb29b@rqc.ru>
On 09/15/2017 11:50 AM, Marat Khalili wrote:
> May I state my user's point of view:
>
> I know one applications that uses O_DIRECT, and it is subtly broken
> on BTRFS. I know no applications that use O_DIRECT and are not
> broken. (Really more statistics would help here, probably some exist
> that provably work.) According to developers making O_DIRECT work on
> BTRFS is difficult if not impossible. Isn't it time to disable
> O_DIRECT like ZFS does AFAIU? Data safety is certainly more important
> than performance gain it may or may not give some applications.
I agree with you, but it should be sufficient to disable O_DIRECT when the file has the checksums. I was unable to observe filesystem corruption when the checksums are disabled.
The use cases where O_DIRECT is useful are VM and databasesM and in these cases also nodatacsum/nodatacow are useful.
BR
G.Baroncelli
>
> --
>
> With Best Regards, Marat Khalili
>
> -- To unsubscribe from this list: send the line "unsubscribe
> linux-btrfs" in the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
next prev parent reply other threads:[~2017-09-15 17:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-14 22:00 BUG: BTRFS and O_DIRECT could lead to wrong checksum and wrong data Goffredo Baroncelli
2017-09-14 22:18 ` Hugo Mills
2017-09-15 6:04 ` Goffredo Baroncelli
2017-09-15 8:26 ` Hugo Mills
2017-09-15 9:50 ` Marat Khalili
2017-09-15 10:12 ` Paul Jones
2017-09-15 17:37 ` Goffredo Baroncelli [this message]
2017-09-15 17:14 ` Goffredo Baroncelli
2017-09-15 3:55 ` Andrei Borzenkov
2017-09-15 5:50 ` Goffredo Baroncelli
2017-09-15 17:01 ` Andrei Borzenkov
2017-09-15 17:30 ` Goffredo Baroncelli
2017-09-15 17:01 ` Liu Bo
2017-09-15 18:57 ` Goffredo Baroncelli
2017-09-15 19:14 ` Liu Bo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=dae5a361-6ff4-c64c-81fa-ed58b1d54dff@inwind.it \
--to=kreijack@inwind.it \
--cc=hugo@carfax.org.uk \
--cc=linux-btrfs@vger.kernel.org \
--cc=mkh@rqc.ru \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox